Multi-position solenoid and control circuit



L. H. MICHAELS MULTI-POSITION SOLENOID AND CONTROL CIRCUIT Jan. 21, 1969 Filed Aug. 10, 1966 INVENTOR Z 44,11)/ ATTORNEYS BY )(M,

United States Patent 3,423,020 MULTI-POSITION SOLENOID AND CONTROL CIRCUIT Leonard H. Michaels, Justice, 111., assignor to Harper- Wyman Company, Hinsdale, 111., a corporation of Illinois Filed Aug. 10, 1966, Ser. No. 571,503 US. Cl. 236-15 15 Claims Int. Cl. Gd 23/20 ABSTRACT OF THE DISCLOSURE Control apparatus including electromagnetically actuating means comprising a movable armature with first and second movable armature portions that are mechanically interconnected for limited relative movement and in which selected energization of the electromagnetic actuating means effects predetermined movements of an armature portion. The armature is operatively connected as to a valve element movable from an off to predetermined low and high flow positions to control, for example, the flow of gas to provide continuous flow of gas to the burner at either high or low rate.

The present invention relates to control apparatus and has for its primary object the provision of a new and improved electromagnetic valve means together with an associated control selectively operable to provide gas at different flow rates under thermostatic control as to the broiler burner of a gas range oven.

Another object of the invention is to provide a solenoid having an armature constructed and arranged to be moved from an initial off position to a plurality of different open positions depending upon the degree of energization of the solenoid winding.

A further object of the invention is the provision of a new and improved solenoid of the type set forth in the preceding paragraph in which the armature includes first and second relatively movable and operatively interconnected portions so constructed and arranged that one armature portion is moved from an initial off to a first open position when the winding is energized to a lesser degree and to a second open position when the winding is energized to a greater degree.

Another object of the invention is to provide a new and improved solenoid valve in which the solenoid is constructed and arranged as set forth in the preceding paragraph.

A further object of the present invention is to provide a control system particularly adapted for the broiler burner of an oven and including the electromagnetic valve means of the invention in association with temperature responsive means for selective energization for the maintenance of high and low rates of gas flow to the broiler burner, whereby a continuous flame broil is effected.

Accordingly, a further object of the present invention is to provide a gas range oven with an electrically controlled continuous broil in an economical and reliable manner.

A still further object of the invention is the provision of a new and improved control for a broiler burner including, a selectively energizable electromagnetic valve operable from an initial ofl? to a first and low gas flow position and to a second on high gas flow position depending upon its degree of energization, and means including temperature responsive means for selectively controlling the energization of said electromagnetic valve for determining its position and providing a continuous flow of gas to the broiler burner at either a high or low rate "ice whereby the broiler burner may be operated with a continuous flame.

In brief, the control apparatus of the invention comprises an electromagnetic valve means adapted selectively to be opened to different positions as by selective energization and operation of an armature including movable first and second armature portions interconnected for limited relative movement. The armature is conveniently made in two telescopically arranged portions. When, for example, full voltage is applied, the flux generated is suflicient to move both armature parts to limit positions so that a second portion of the two, which is connected to a device to be operated, as such a valve element, is moved to what may be defined as its full on position. When a lesser voltage such as half the full voltage is applied, the flux generated is only suflicient to move the first armature portion which, in turn, moves the second armature portion a limited extent whereby the valve is opened only partially to provide a lesser rate of flow of gas. The lesser fiow of gas can be adjusted by movement of a normal stationary valve seat relative to a movable valve element. The valve means is especially suitable for electrical control of the flow of gas to the broiler burner of an oven to provide a continuous flame broil which is desirable for the purpose of consumption of smoke produced during broiling and for enhancing the browning process. Accordingly, the arrangement provides an electrical control for continuous broil in an economical and reliable manner.

Other objects and advantages of the present invention will become apparent from the ensuing description of illustrative embodiments thereof, in the course of which reference is had to the accompanying drawing, in which FIG. 1 is a diagramatic and schematic representation of the invention applied to the oven of a gas range equipped with a selectively usable low bake burner and a high broiler burner;

FIG. 2 is a largely cross sectional view then through the solenoid valve of the present invention and which may be incorporated in the embodiment illustrated in FIG. 1, the view illustrating the valve in its initial or closed position.

FIGS. 3 and 4 are enlarged fragmentary cross-sectional view of the valve of FIG. 2 illustrating it in low and full on positions; and

FIG. 5 is a fragmentary view of an alternative form of solenoid armature which may be utilized.

Referring now to the drawing and first to FIG. 1 the present invention is illustrated as embodied in a gas range 10 having a single cavity oven 12 in which are located, in known manner, a lower bake burner 14 and an upper broiler burner 16. The burners are adapted to be ignited in known manner. For example, the bake burner may be ignited by a continuous pilot 18 continuously supplied with gas in conventional manner, not shown. The presence of a frame at the pilot burner is detected by flame responsive means 20 of known type adapted to control a flame switch 22 which is in circuit closing position, as indicated, when a flame is present at the pilot burner. In similar manner the broiler burner has a continuous pilot 24 for igniting it. A flame responsive means 26 is provided for closing flame switch 28 when the continuous pilot 22 is ignited. If desired pilot burner 22 may be of an aerated type disclosed and named in the copending application of Crannell & Shelton, Ser. No. 400,526 filed Sept. 30, 1964.

The oven cavity 12 has temperature responsive means 30 of known construction located therein and which is adapted to open and close switch 32 forming part of a thermostatic control indicated as a whole by reference character 34 of known type, and including a temperature selecting and adjusting knob 36 which is also operable initially to close switch 32 when it is desired to place either the back or broiler burners in operation.

Gas is supplied to the burners through a conduit 40 under the control of a manually operable shut-off valve 42. Gas is supplied to the bake burner through a conduit 44 having interposed therein a flow controlling electromagnetic or solenoid valve 46 of known type and which is adapted when energized to open a valve so that gas will flow to the bake burner.

Similarly, gas is supplied to the broiler burner through conduit 48 having interposed therein the electromagnetic valve means 50 of the present invention and which will be described in detail herein but which is adapted to supply gas to the broiler burner so as to provide a continuous broil flame.

The control also includes a bake broil selector 52 illustrated in its broil position but operable to an indicated bake position. The selector includes an indicator 54 operable simultaneously with the switches 56 and 58. Power, such as the usual 110 volts A.C., is supplied to the circuit through input lines 60 and 62. Line 60 is connected by conductor 64 to the electromagnetic valve means 50 and by conductor 66 to a terminal of the solenoid valve 46. The other terminal of the latter is connected by conductor 68 to flame switch 22 from which conductor 70 leads to terminal 72 associated with switch blade 56 of selector 52. The switch blade 56 engaged terminal 72 when the bake burner is selected, as illustrated. In this event the solenoid valve 46 is under the control not only of the flame switch 22 but also of the thermostat switch 32 which is connected to switch blade 56 through conductor 74 and to power line 62 by conductor 76. Accordingly, when the bake portion is selected gas it is supplied to the bake burner upon opening of the solenoid valve 46 under control of the oven thermostat 30 and switch 32. As indicated, operation occurs at a temperature selected by the temperature control knob 36. The flame responsive device 20 and switch 22 constitute asafety device deenergizing the solenoid valve 46 in the event of extenguishment of the pilot burner 18.

The electromagnetic valve means 50 of the present in vention is arranged to be selectively operable from an initial off to a first and low gas flow position and to a second and high gas flow position in response to the temperature responsive means 30 thereby to provide a continuous flow of gas to the broiler burner at either a high or low rate whereby the broiler burner operates with a continuous flame, which is desirable for the purpose of consuming smoke and for browning the food to be broiled. Further details of an electromagnetic means which can be utilized and which forms part of the present invention will be described later in conjunction with FIGS. 2, 3 and 4.

Referring further to FIG. 1, it will be noted that conductor 80 leads from the electromagnetic means 50 to the broil burner flame switch 26. The latter is also connected by conductor 82 to switch blade 56 of selector switch 52 whereby the electromagnetic means 50 is placed under control of the thermostatic control 34. In the present embodiment, which will be described in detail shortly, the selective operation of the electromagnetic valve means 50 is also controlled by switch blade 58 connected through resistor 84 and conductor 86 to power line 62. Switch blade 58 in its indicated position is also connected by conductor 88 to conductor 82.

The described arrangement is such that when the broil operation is selected the thermostatically operated switch blade 32 is eflective in its illustrated closed position to short circuit resistor 84, but when switch blade 32 is opened, the resistor 84 is placed in series with the electromagnetic device 50. When the resistor is short circuited the electromagnetic device 50 supplies gas at the high flow rate to the broiler burner. When the resistor 84 is in circuit and in series with the valve means gas is supplied at a reduced or low rate to the broil burner. The low rate is sufficient to maintain a broiler flame and the temperature adequate to consume the smoke from the food being broiled, which is a temperature somewhat below the selected broil temperature.

The electromagnetic valve means 50 may be of various constructions but the construction illustrated in FIGS. 2, 3 and 4 has been found to be satisfactory in operation as well as economical to build and install. The valve means is what may be considered to be a multi-position electromagnetic or solenoid type valve characterized by a single winding having associated with it a multipart armature constructed and arranged to move a gas flow controlling movable valve element from an initial oif to a first open or low flame position or to a second open and high flame position depending upon the energization of the winding, which may be suitably energized as at full or half line voltage.

Referring now to FIGS. 2, 3 and 4, electromagnetic device 50 comprises a body which may be of die cast aluminum and a solenoid 102. The valve body has an inlet passageway 104 and an outlet passagewy 106 which are adapted to be, when the device is installed, to be connected to the conduit 48 through which gas is supplied to the broiler burner. The valve body has mounted in it an adjustable valve seat element 108, one end 110 of which forms a stationary valve seat with which is associated a movable valve element 112 operated by the solenoid 102, The seat structure includes an angular inlet passageway 114 and an axial outlet passageway 118 leading to the valve seat and to valve chamber 120 which communicates with the outlet passageway 106 and in which the movable valve element is located.

The solenoid valve includes a coil or winding 122 surrounded by a suitable molded insulating material 124 through which the conductors 64 and 80 extend for connection with the circuit. It has a conventional magnetic housing 126 in the form of a closure encircling the coil and having a top portion 128 and a base 130, the latter of which may be secured by bolts 132 to the valve body 100 and to a mounting bracket structure 134. A sealing gasket 136 is placed between the valve body and the base portion 130.

The solenoid includes a multipart core or armature indicated as a whole by reference character 140 including a first portion 142 and a second portion 144 which are telescopically arranged for limited relative movement with respect to each other and which are both movable coaxially of the coil 122 when coil is energized, in a manner described shortly. They are slidably mounted centrally within a nonmagnetic sleeve 146 extending from base portion 130 to the top 128. The lower end of the sleeve is provided with a flange 146 abutting against an inset portion 148 of base 130 whereby the lower ends may be readily secured together as by welding.

The upper end of the sleeve 146 encircles and is secured to central structure 150 extending downwardly from top 128. It serves to locate and hold the upper end of the sleeve and has secured to its inner end rivet like abutment 152 having a rounded end 154 defining a limit position for armature portion 142. The central portion of abutment 152 above the end 154 is surrounded by a copper shading coil 156.

The movable valve element 112 may be formed of suitable material such as silicone rubber and it is attached to the end of armature portion 144 as by a washer 158 secured to the armature. The armature and the valve seat are biased to move the movable valve element 112 into engagement with the valve seat 110, i.e., to the closed position of the valve by a helical spring 160 engaging the valve element and the solenoid housing 130.

The armature 140 is, as heretofore indicated, made of the two parts 142 and 144 arranged for limited relative movement They are telescopically related by construction of the armature portion 142 with a reduced diameter portion 162 for close encirclement by portion 164 of the lower armature portion 144.

Limited relative movement between the two is provided as by a pin and slot type of connection including a pin 166 extending through armature portion 142 so that its outer ends project into a slot 168 in the encircling portion 164 to armature 144. The armature portion 144 is provided with a projecting pin 170 of magnetic material which abuts the flat surface 172 in the armature portion 144. This surface 172 should be made as smooth as possible to provide good contact for quiet operation which is enhanced by the shading ring 174 surrounding the abutment pin 170.

In the off position illustrated in FIG. 2 the two armature portions are in their lowermost positions and in abutting contact through the pin 174 and surface 172. At the same time the movable valve element 112 is held in its closed position by spring 160.

When the coil 122 is fully energized, as at full strength, it would be the case when the switches 56 and 32 are both closed to short circuit resistor 84, the coil generates sufflicient magnetic flux to effect upward movement of both armature portions against the force of spring 160. In this case the valve is operated to its fully open position. When the magnetic flux produced by the coil is reduced as by reduction of the voltage applied to the coil by insertion of resistor 84 in circuit with it, the armature element 144 moves downwardly a limited extent because the flux is not sufficient to maintain it in its limit position which is indicated in FIG. 4. The extent of movement as determined by the relative movement provided by the pin and slot connection and is illustrated in FIG. 3 from which it may be noted that the valve element 12 is in a partially closed position to provide the reduced flow of gas. This flow may be adjusted or regulated by movement of the valve seat defining element 108.

Should the winding 122 be energized at a reduced rate initially, the armature portion 142 alone will be moved against the abutment 152-154 as indicated in FIG. 3 and armature portion 144 is moved only a limited extent, this movement being effected through the pin and slot connection 166-168.

In operation, valve 42 is opened and the continuous pilots 18 and 22 are lighted and the flame switches 22 and 28 controlled thereby are actuated to their circuit closing positions. If it is desired to supply gas to the broiler burner the selector switch 52 is operated to its indicated broil position in which switches 56 and 58 are closed and connected to conductor 82 and through flame switch 26 to the winding of valve means 50. In the event the temperature in the oven cavity 12 is below the broil temperature selected by operation of knob 36, the switch 32 will be closed so that resistor 84 will effectively be short circuited. The coil 122 is thus energized at full voltage and the valve 112 is moved to its full open position as illustrated in FIG. 4 by conjoint movement of both armature portions by the flux generated by the winding. Gas is thus supplied to the .broiler burner 16 where it is ignited by the pilot 22. After the selected broil temperature has been attained the temperature responsive means 30 opens the switch 32 with the result that resistor 84 is placed in series with coil 122 to reduce the current flow through it. This results in release and movement of the second armature portion 144 under the influence of spring 160 to the position shown in FIG. 3 so that gas is supplied at a reduced rate to the broil burner. Thereafter the gas may be supplied at this lower rate or should the oven temperature decrease and temperature responsive means close switch 32, then the armature portion 144 will be returned to the position shown in FIG. 4 and gas again supplied at a full rate to the broiler burner. A continuous flame broil is thus provided in a simple and economical manner.

In the event it is desired to bake then gas is supplied to the bake burner 14 under the control of the thermostatic means 30 and the solenoid operated valve 46 in conventional manner.

An alternative armature construction is described in FIG. 5 to which reference may now be had. It includes the two armature portions 200 and 202, which are telescopically arranged for limited relative movement. Armature portion 200 has a portion 204 of intermediate diameter and an end portion 206 of the small diameter and having projecting abutment defining end 208 adapted to engage the adjacent end 210 to armature portion 202. Portion 206 is surrounded by a copper shading coil 212 and by tubular element 214 which is press-fitted on to portion 204 of armature element 200. The relative movement is provided by securing to the end of armature element 202 an aperture cop like element 218 having one end press-fitted on to a shoulder portion 220 of armature portion 202. The opposite end is formed with an internal flange 222 closely encircling armature portion 204 whereby a sliding fit is provided between two armature portions. The extent of relative movement is determined by abutment of flange with armature 200 and the end of the filler sleeve 214, respectively.

It will be seen that the alternative construction of FIG. 5 is in many respects similar to that of the armature earlier described and that its operation is substantially the same so that further description of the portion is not deemed necessary.

It should be mentioned that the electromagnetic device 50 and the present invention and the solenoid operated valve 46 may be combined into a single unit embodying both valves. Such a unit could have a single inlet and two outlets, one controlled by the solenoid valve 46 and the other by the device 50 of the present invention.

While the present invention has been described in connection with the details of illustrative embodiments, it should be understood that such details are not intended to be limitative of the invention except insofar as set forth in the accompanying claims.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Control apparatus comprising:

electromagnetic actuating means operable at greater and lesser levels of energization for producing magnetic fields of greater and lesser strength;

an armature means operated by said actuating means and including first and second relatively movable portions constructed and arranged relative to said actuating means such that said first portion is magnetically movable in response to said lesser energization level and said second portion is magnetically movable only in response to said greater energization level;

means limiting the movement of said first portion to a first distance;

and a mechanical connecton between said portions limiting relative movement therebetween to a distance smaller than the first distance.

2. Control apparatus as claimed in claim 1 wherein said actuating means includes a single coil.

3. Control apparatus as claimed in claim 1 wherein said first armature portion is electromagnetically actuated to a limit position in response to said greater energization and it moves the second armature portion to a predetermined first position through said connection.

4. Control apparatus as claimed in claim 1 wherein both the first and second armature portions are electromagnetically actuatable in response to said greater energization to move the second armature portion to a second predetermined position.

5. Control apparatus as claimed in claim 4 wherein the second of the armature portions is returned to its first position when said greater energization is reduced to said lesser energization.

6. Control apparatus as claimed in claim 5 wherein the armature portions are generally aligned and cylindrical and include adjoining parts in telescopic sliding relation and the connection between them is a lost motion connection.

7. Control apparatus as claimed 6 wherein the lost motion connection is constituted by a pin and slot connection.

8. Control apparatus as claimed 6 wherein the lost motion connection is constituted by annular groove structure on one portion and a flange on the second portion eX- tending into said groove.

9. Control apparatus as claimed in claim 3 wherein said limit position is determined by stop defining means engageable by the first armature portion.

10. Control apparatus as claimed in claim 6 wherein a limit position of the first armature portion is determined by stop defining means.

11. Control apparatus as claimed in claim 10 including a shading coil associated with said stop defining means and another shading coil associated with the end armature portion adjacent to the adjoining end of the second armature position.

12. Flow control apparatus comprising a valve seat, a valve element cooperating with said valve seat to control flow therethrough, means resiliently biasing said valve element against said valve seat, reciprocally movable armature means including first and second relatively movable portions, said second portion operably connected to said valve element, an electromagnetic coil means operable at a first energization level for magnetically moving only said first armature portion a first distance, a lost motion connection between said first and second portions limiting relative movement therebetween to a distance smaller than said first distance for moving said valve element to a partly open position in response to energization of said electromagnetic coil means at said first level, and said electromagnetic coil means being operable at a second energization level for magnetically moving said second portion relative to said first portion thereby to move said valve element to a fully opened position.

13. Control apparatus as claimed in claim 12 including temperature responsive means for controlling the selective energization of the electromagnetic coil means.

14. Control apparatus as claimed in claim 13 wherein said electromatic coil means includes a single coil and the energization controlling means includes resistance means selectively placed in circuit with the coil.

15. Control apparatus as claimed in claim 13 for a gas burner and wherein the valve element controls the flow of gas to the burner to provide selected high and low rates of flow of gas to the burner.

References Cited UNITED STATES PATENTS 2,611,542 9/1952 Crum et a1. 236-68 2,617,050 11/ 1952 Weinfurt 335-279 X 2,654,393 10/1953 Chormley 335-261 X 2,919,858 l/1960 Matthews 236-1 2,979,643 4/1961 De Wilde et al 335-261 3,050,255 8/ 1962 Willson et al 236-1 3,006,373 10/1961 Ehlke 251-138 X 3,216,449 10/ 1965 Maudlin et al 236-74 X ROBERT A. OLEARY, Primary Examiner.

WILLIAM E. WAYNER, Assistant Examiner.

US. Cl. X.R. 

